---
id: CVE-2026-105797
title: >-
  SimpleChat is a secure AI conversation application with personal and group
  workspaces for document-grounded interactions
summary: >-
  SimpleChat is a secure AI conversation application with personal and group
  workspaces for document-grounded interactions. In versions 0.261.003 and
  0.261.027, an authorization ordering flaw in POST /api/user/plugins allows an
  authenticat…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-78
  - CWE-863
vendor: microsoft
product: simplechat
affected:
  - simplechat < 0.261.031
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T15:25:00.650'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-105797'
references:
  - url: >-
      https://github.com/microsoft/simplechat/commit/73ff7d6998dc4827a0f6ba002386275a7c1ec804
    label: security-advisories@github.com
  - url: >-
      https://github.com/microsoft/simplechat/security/advisories/GHSA-h4mw-qw8m-5x4j
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-06T15:01:49.305Z'
---

## Overview

SimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions. In versions 0.261.003 and 0.261.027, an authorization ordering flaw in POST /api/user/plugins allows an authenticated low-privileged user to omit the top-level MCP type so that _reject_non_admin_mcp_stdio skips inspection before the type is restored from metadata. The stored personal action can then reach McpPluginFactory.create_connector, and MCPStdioPlugin.connect starts the attacker-selected operating-system process under the application service identity when the action tool is invoked. Exploitation requires personal plugins to be enabled and governance to permit MCP actions, and it can expose or modify secrets and data available to the service or disrupt the service. This issue is fixed in version 0.261.031.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.